Benjamin M. Zuckerman

Professor of Astronomy
UCLA

Office: 3-929 PAB
Phone: (310) 825-9338
email

Ben Zuckerman’s Astronomy Web Page

• S.B., Physics, Massachusetts Institute of Technology, 1963
• S.M., Aeronautics & Astronautics, Massachusetts Institute of Technology, 1963
• Ph.D., Astronomy, Harvard University, 1968

At ages of tens of millions of years, terrestrial planets are likely still accumulating and Jupiter-like planets that have already formed will still be warm and radiating away, at infrared wavelengths, their heat of formation. Such warm "Jupiters", if they exist, should be detectable with sensitive instruments and techniques (such as adaptive optics) on large ground-based telescopes near the young stars identified by Prof. Zuckerman's group. These stars are also prime targets for space based telescopes such as the Hubble Space Telescope, and the Spitzer Infrared Observatory. When flying, the SOFIA airborne infrared observatory will also target many of these youthful stars.

The probable first-ever imaging detection of a planet in orbit around an object other than our Sun was recently reported

http://www.eso.org/outreach/press-rel/pr-2004/pr-23-04.html

The likely planet, which would have a mass about five times that of Jupiter, orbits a 25 Jupiter mass brown dwarf member of the 8 Myr old TW Hydrae Association. Professor Zuckerman was a member of the joint French/American team that imaged the planet; the paper reporting the discovery is published in the journal Astronomy & Astrophysics (see list below for reference). At present the only technique that astronomers have at their disposal to detect extra-solar planets at separations similar to or greater than the separation between the Sun and Neptune is by imaging very young stars at infrared wavelengths.

In addition to the promise they hold for future investigations of forming planetary systems, the young nearby stars are of interest in their own right. Study of groups of stars that formed together and are moving together through space has played a critical role in the history and advancement of astronomy. Until about 6 years ago only two stellar groups were known within about 200 light years of Earth, and neither group is especially young. Since then Dr. Zuckerman's team has identified four more co-moving groups within 200 light years, all of which are very young (estimated ages lie between about 8 and 50 million years) and each of which contains at least a few dozen stars plus perhaps a brown dwarf or two. The TW Hydrae Association was the first of the four to be identified. Surprisingly, the AB Doradus moving group which is the closest of these four groups to Earth, was the most recent to be identified (see below for reference to the 2004 discovery paper in the Astrophysical Journal).

These groups will tell us much about the astrophysics of young stars and about the recent history of star formation in what is now the solar vicinity of the Milky Way galaxy. A summary of what is known about these groups as of mid-2004 may be found in the reference "Young Stars Near the Sun" listed below.

• "Dusty Circumstellar Disks", Annual Review of Astronomy & Astrophysics 39, 549, 2001
• "Why SETI will fail", Mercury 31, 15, 2002 (September-October issue)
• "Metal Lines in DA White Dwarfs", Zuckerman, B., Koester, D., Reid, I. N., Hünsch, M., Astrophysical Journal, 596, 477, 2003
• "Dusty Debris Disks as Signposts of Planets: Implications for Spitzer Space Telescope", Zuckerman, B., Song, I, Astrophysical Journal, 603, 738, 2004
• "The AB Doradus Moving Group", Zuckerman, B. Song, I., Bessell, M. S., Astrophysical Journal, 613, L65, 2004
• "Young stars near the Sun.", Zuckerman, B., Song, I., Annual Review of Astronomy & Astrophysics, 42, 685, 2004
• "A Giant planet candidate near a young brown dwarf", Chauvin, G. and 7 others including B. Zuckerman, Astronomy & Astrophysics, 425, L29, 2004

In addition to the above research papers, Prof. Zuckerman has edited two books that deal with exciting astronomical topics ("Extraterrestrials, Where Are They?" and "The Origin and Evolution of the Universe") and another ("Human Population and the Environmental Crisis") that concerns the major problem of our time.

To illustrate one astronomy-related aspect of a world "civilization" seriously out of whack, consider a peopled mission to Mars, a wonderful project that would enlighten the spirit and knowledge of all mankind. According to leaders of the Mars Society, such a mission would cost of order 30 billion dollars. This may sound expensive, but when one realizes that in a typical year the USA spends 10 times this amount on its military budget, and such military expenditures go on year after year after year, by comparison $30 billion is not much money. Yet, a peopled mission to Mars is very unlikely in the foreseeable future. This huge imbalance in spending between something so fundamentally negative as the military and something so positive as exploration of Mars, is a sad and ultimately dangerous commentary on our country and the world.

Current annual U.S. expenditure on astronomy is significantly less than the cost of a Mars mission. But if the U.S. and world environments become stressed too severely, then support of astronomy at anything like current levels may one day be regarded as an unaffordable luxury.